New Buckeye Measurements

[John Atkinson]

The promised follow-up on the Buckeye Purifi Eigentakt 1ET9040BA amplifier has been published in the June 2025 issue of Stereophile.

You can find my measurements at https://www.stereophile.com/content...ba-monoblock-power-amplifier-new-measurements
and Kal Rubinson's report on his auditioning at https://www.stereophile.com/content...040ba-monoblock-power-amplifier-new-auditions

John Atkinson
Technical Editor, Stereophile

​

 

[charlielaub]

Thank you for posting the links to these reviews and measurements. Worth the read, and I am glad that you (John) will consider such a product with an open mind, one that is not all that "esoteric", nor with a stratospheric price tag, but that performs exceptionally well.

Sadly, below your article I had to experience reader feedback like this gem:

"The result? A full 75dB of feedback..." is why Eigentakt amp modules will never regarded as hi-fi. 75 freakin' dB of feedback. It also sounds terrible, very grey and lifeless due I suspect to the low pass filter (greyness) combined with that absolutely bonkers amount of feedback (lifelessness).

I keep hearing he's a great EE, so why can't he make a stable amp without gobsmacking amounts of feedback? He also needs to move the switching frequency into the GHz range to get the low pass filter a lot higher in order to address the phase issues of his amps.

I hope this snooty reader will return to the safety of their Burmesters tout de suite before they suffer any further emotional harm...

 

[Mort]

Luckily I can stay here at ASR and skip stuff like that.

 

[norman bates]

Intermod looks waaaaaayyyyy better.
I would have thought it would sound more blended or instruments blurring together before it was fixed.

And harmonic distortion was amazing b4.

 

[welwynnick]

The promised follow-up on the Buckeye Purifi Eigentakt 1ET9040BA amplifier has been published in the June 2025 issue of Stereophile.
You can find my measurements at https://www.stereophile.com/content...ba-monoblock-power-amplifier-new-measurements
and Kal Rubinson's report on his auditioning at https://www.stereophile.com/content...040ba-monoblock-power-amplifier-new-auditions

Many thanks John, that's much more like what everyone was anticipating.

I'm scratching around to think of ANY other power amplifier at any price with better measurements?
Parasound JC1+? Boulder 2150? McIntosh MC462? Moon 861? All very expensive and very wonderful but not quite there.
The second round of measurements of the Linn Klimax Solo 800 are close, but I think the Benchmark AHB2 still rules.

 

[Kal Rubinson]

I would have thought it would sound more blended or instruments blurring together before it was fixed.

"It is extremely unlikely that any playback of acoustical instruments and human voices contains that kind of energy (19+20kHz signals at 50W peak)"

 

[norman bates]

Yes, but I’m thinking of intermod of say 2k and 3k, with false spikes at 1k/4k, etc……

 

[Travis]

The promised follow-up on the Buckeye Purifi Eigentakt 1ET9040BA amplifier has been published in the June 2025 issue of Stereophile.

You can find my measurements at https://www.stereophile.com/content...ba-monoblock-power-amplifier-new-measurements
and Kal Rubinson's report on his auditioning at https://www.stereophile.com/content...040ba-monoblock-power-amplifier-new-auditions

John Atkinson
Technical Editor, Stereophile

​

Thank you, enjoyed the updates.

 

[Timcognito]

Thanks to JA and KR for an entertaining and insightful read, as always. My subscription to Stereophile lapsed years ago and nice see you guys still got it. Also fun to read the comments a know the cranks are still hanging on over there.

 

[amper42]

The promised follow-up on the Buckeye Purifi Eigentakt 1ET9040BA amplifier has been published in the June 2025 issue of Stereophile.

You can find my measurements at https://www.stereophile.com/content...ba-monoblock-power-amplifier-new-measurements
and Kal Rubinson's report on his auditioning at https://www.stereophile.com/content...040ba-monoblock-power-amplifier-new-auditions

John Atkinson
Technical Editor, Stereophile

​

Hi,
What was the input impedance measurement on the 2nd set of tests? I noticed Buckeye removed that specification on his site after the initial test. Thank you!

 

[Kal Rubinson]

Yes, but I’m thinking of intermod of say 2k and 3k, with false spikes at 1k/4k, etc……

I do not see any reason for that concern unless, in view of what we know, you have low expections for performance at 2k/3k.

 

[Buckeye Amps]

Hi,
What was the input impedance measurement on the 2nd set of tests? I noticed Buckeye removed that specification on his site after the initial test. Thank you!

It is 10k

 

[David_M]

It is 10k

Congratulations on the new and excellent IMD measurements. One of the best, if not the very best I've seen so far. Should one assume these specs are representative of all your 9040BA amps?

 

[Buckeye Amps]

Congratulations on the new and excellent IMD measurements. One of the best, if not the very best I've seen so far. Should one assume these specs are representative of all your 9040BA amps?

Yes, nothing special was done for these units sent back to Stereophile other than replacing the faulty module

 

[David_M]

Many thanks John, that's much more like what everyone was anticipating.

I'm scratching around to think of ANY other power amplifier at any price with better measurements?
Parasound JC1+? Boulder 2150? McIntosh MC462? Moon 861? All very expensive and very wonderful but not quite there.
The second round of measurements of the Linn Klimax Solo 800 are close, but I think the Benchmark AHB2 still rules.

Are you sure about that? Benchmark AHB2 (LEFT) and Buckeye Purifi 9040BA (RIGHT) ...courtesy of Stereophile magazine

 

[Sokel]

That's really representative of the amp, justifying a flagship module.
Endgame for some I guess.

Many thanks John, that's much more like what everyone was anticipating.

I'm scratching around to think of ANY other power amplifier at any price with better measurements?
Parasound JC1+? Boulder 2150? McIntosh MC462? Moon 861? All very expensive and very wonderful but not quite there.
The second round of measurements of the Linn Klimax Solo 800 are close, but I think the Benchmark AHB2 still rules.

Quick and dirty, the one I can think of is Halcro Eclipse Mono at its current mode input:

Eclipse mono : HALCRO

The world's only Super-Fidelity audio

halcro.com

 

[tmtomh]

Glad to see this - and I hope these new measurements get as much attention as the originals did.

Furthermore, I'd love to see some of the folks who were so insistent on spreading FUD about this after the original measurements come to this thread to acknowledge their suspicions of anything other than a defective module have turned out to be unfounded.

 

[Descartes]

The promised follow-up on the Buckeye Purifi Eigentakt 1ET9040BA amplifier has been published in the June 2025 issue of Stereophile.

You can find my measurements at https://www.stereophile.com/content...ba-monoblock-power-amplifier-new-measurements
and Kal Rubinson's report on his auditioning at https://www.stereophile.com/content...040ba-monoblock-power-amplifier-new-auditions

John Atkinson
Technical Editor, Stereophile

​

Does Kal still have Blade Meta 2?

 

[Descartes]

Are you sure about that? Benchmark AHB2 (LEFT) and Buckeye Purifi 9040BA (RIGHT) ...courtesy of Stereophile magazine

View attachment 452261View attachment 452262

So does this means Buckeye are better?

 

[Kal Rubinson]

Does Kal still have Blade Meta 2?

I do.